CIA Director Gina Haspel is expected to give a closed briefing to US senators on the murder of Saudi journalist Jamal Khashoggi, Reuters and the Wall Street Journal said on Monday, citing people familiar with the matter.

Haspel will brief the Republican and Democratic leaders of the Senate Foreign Relations, Armed Services and Appropriations committees, a source told Reuters, adding that the Senate Intelligence Committee already had been briefed by the CIA chief.

Her scheduled meeting on Tuesday comes after lawmakers were angered that she didn't participate in a briefing on Saudi Arabia last week.

It was reported at the time that the White House barred Haspel from that meeting, which was attended instead by US Secretary of State Mike Pompeo and Defence Secretary Jim Mattis.

But a CIA spokesman last week denied that she was prohibited from attending.

"The notion that anyone told director Haspel not to attend today's briefing is false," Timothy Barrett said in a statement.

Rift between CIA, Trump administration

Khashoggi, a Saudi government critic and columnist for the Washington Post, was killed on 2 October inside the Saudi consulate in Istanbul.

The case has highlighted a growing rift between US President Donald Trump's administration and the US intelligence agency, which concluded last month that Saudi Crown Prince Mohammed bin Salman – the country’s de-facto ruler – ordered his murder.

Trump has repeatedly cast doubts over that assessment and last month vowed to stand by Saudi leaders, including MBS, despite the killing.

"Our intelligence agencies continue to assess all information, but it could very well be that the crown prince had knowledge of this tragic event – maybe he did and maybe he didn't!" Trump said in a written statement on 20 November.

Haspel's scheduled meeting comes after lawmakers were angered that she didn't participate in a briefing on Saudi Arabia last week (AFP)

While Saudi officials have repeatedly denied the crown prince knew anything about Khashoggi's murder and its subsequent cover-up, human rights groups, journalists, UN experts and others have pointed the finger at bin Salman, saying it's impossible he was not involved.

Pompeo, who met with US senators last Wednesday to try to prevent a resolution to withdraw US backing for a Saudi-led coalition in Yemen, has said he has read all the intelligence regarding Khashoggi's murder.

"There is no direct reporting connecting the crown prince to the order to murder Jamal Khashoggi," Pompeo told reporters last week.

Haspel's trip to Turkey

The CIA assessment says its conclusion that MBS ordered Khashoggi's assassination is based on the crown prince's personal interest in the journalist, his tight control over the Saudi operatives sent to Istanbul to kill him "and his authorising some of the same operators to violently target other opponents," the WSJ reported on Saturday.

US lawmakers have demanded that Haspel be allowed to brief them on the CIA's findings in the Khashoggi case.

Last week, Republican Senator Lindsey Graham said the briefing with Pompeo and Mattis was "inadequate" because the CIA did not participate.

“So the question for me is whether or not the CIA supports the conclusion with a high degree of confidence that the crown prince was complicit in the murder of Mr Khashoggi," Graham told reporters. “I understand the strategic relationship between us and Saudi Arabia, but I am not going to blow past this."

Haspel has also been briefed on the Turkish investigation into Khashoggi's murder, travelling to the capital, Ankara, in late October for talks with officials there.

Turkish intelligence shared "all the evidence" relating to Khashoggi's murder with Haspel, Turkish news outlets supportive of the government reported at the time.

Video images and audio tapes, as well as evidence gathered from the consulate and the consul's residence, were shared with Haspel during the briefing at the Turkish intelligence organisation (MIT), Sabah newspaper reported.

A Turkish source who listened in full to the audio recording has told Middle East Eye that Khashoggi was killed in seven minutes and his body was dismembered inside the Saudi consulate.

Turkish police also searched the kingdom's Istanbul consulate and the consul general's residence and looked for evidence in an Istanbul forest.

The killing of Khashoggi has strained Saudi Arabia's ties with several Western countries and battered the crown prince's image abroad.